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 共查询到20条相似文献,搜索用时 109 毫秒
1.
CoherenceTimeMeasurementofPicosecondPulsesUsingReverseSaturableAbsorptioninLeadPhthalocyanineLIFengSONGYinglinYANGKunLUIShuti...  相似文献   

2.
DirectGenerationofTunableUVPicosecondLaserPulsesUsingSpectrotemporalSelectionNguyenDaiHung1)YusaburoSegawa(PhotodynamicResea...  相似文献   

3.
ASoftX┐rayStreakCamerawithSlitLengthof30mmQUJunleNIUHanben(XianInstituteofOpticsandPrecisionMechanics,ChineseAcademyofScienc...  相似文献   

4.
Surface temperature field survey for laser heating of steels   总被引:2,自引:0,他引:2  
Surfacetemperaturefieldsurveyforlaserheatingofsteels¥ZHUZuchang;LIXiuqian;YUShaoluo(ShanghaiUniversityofEngineeringScience,Sh...  相似文献   

5.
TheoryofdischargesectionalizedalongagasflowCHENTao;QIUJunlin(LaserInstituteofHuazhongUniversityofScience&Technology,mahan4300...  相似文献   

6.
PedestalMeasurementofLaserPulsesWANGYiminZHANGZhengquanXUZhizhan(ShanghaiInstituteofOptics&FineMechanics,ChineseAcademyofScie...  相似文献   

7.
PropertiesofLBOandGenerationofMode┐lockingBlueFemtosecondPulsesHUANGFeiranWEIZhiyiYANGJieZHOUJianyinYUZhenxin(StateKeyLabora...  相似文献   

8.
TheHardnessPropertiesofCarbonSteelsAfterLaserProcessing¥ZHUZuchang;WANGWeixiang;LIXiuqian;YUShaoluo(ShanghaiUniversityofEngin...  相似文献   

9.
1 INTROEXPERIMENTExperimentalsetupwasshowninFig .1,exhaustivedescriptionsonthesetupandtheprocessofacquiringdatahasalready giveninrelativedocument[1] ,nowwedoexcessivedescriptionnolonger .2 RESULTANDDISCUSSIONResult:earlierspectraoftheplasmaradiatingwereshow…  相似文献   

10.
EfectsofPulseDurationsonHighorderHarmonicGenerationLIXuexinLIUYaqingZHAIKanXUZhizhanHANShensheng(ShanghaiInstituteofOpticsan...  相似文献   

11.
本文描述了以激光为光源测量平板玻璃折射率实验中成像场产生散斑的现象,并获得了一种简单有效的散斑削减方法.理论上激光经过漫散体后产生微光束干涉场,利用统计学的规律,总结出了散斑元之间对比度的影响因素.实验中,选取动-静毛玻璃对作为削减器件,利用静止漫散体增加入射光的粗糙程度,通过缓慢旋转的运动漫散体,可将散斑对比度降为4%左右,使干涉条纹清晰可见.  相似文献   

12.
阐述了飞秒激光脉冲在随机介质传播过程中产生时域散斑的原理,并对时域飞秒散斑进行了测量. 时域飞秒散斑的产生是飞秒脉冲在随机介质中经历多重散射形成的随机干涉现象在时域的体现. 初步讨论了时域散斑的统计特性并给出了相应的实验结果. 关键词: 时域散斑 飞秒脉冲 随机介质  相似文献   

13.
用偏振和有规位相分布抑制线聚焦系统的小尺度不均匀性   总被引:2,自引:0,他引:2  
刘忠永  吕百达 《光学学报》1995,15(12):626-1632
研究了一种用以抑制光楔列线聚焦系统在靶面产生的干涉尖端的方法。由这种尖峰引起的小尺度不均匀性对X射线激光的产生是不利的。利用特殊分布的偏振态和位相,可把尖峰引向更密度伯程度,而且其对比度下降,这将有利于它通过靶物质自身的横向热传导而平滑化。对于四单元的列阵系统,甚至可将尖峰完全消除。  相似文献   

14.
Asundi A 《Optics letters》2000,25(4):218-220
Speckles usually are of two kinds: laser speckle and white-light speckle. An additional kind, termed a sampled speckle, is proposed. Whereas laser speckles arise from multiple interference of light scattered from an object illuminated by a coherent laser beam and white-light speckles are a physically generated speckle pattern on the surface of the object, sampled speckles are generated as a result of the sampling of a digital image. The generation of these speckles and their application to displacement measurement are demonstrated.  相似文献   

15.
郑建洲  蔡邦维 《光学学报》1997,17(11):581-1584
为了检测列阵式靶面均匀照明光学系统聚焦特性,成功地开发了测定微米量级光强度起伏干涉斑纹投影放大的新技术。报道了测定聚焦不斑一维,二维大尺度不均匀性小尺度干涉斑纹的实验方法,结果及误差分析。  相似文献   

16.
在冲击波过程中,利用成像型速度干涉仪探测样品自由面的速度时,散斑的叠加使得干涉曲线被严重干扰,影响了速度信息的精密提取。在理论上从光路的角度分析了系统中可能造成散斑的两种因素:靶面粗糙度和多模光纤。在实验上设计了三种照明方式分别对这两种因素进行验证。离线实验的结果表明,多模光纤的引入对散斑的产生起了主要的作用,这对抑制乃至遏制散斑的产生具有很好的指导性意义。  相似文献   

17.
This paper investigates, experimentally, the dynamic properties of triply-scattered speckled speckles and their application to the velocity measurement of a moving diffuse object, which is behind a transparent diffuse screen. The comparison between triply-scattered speckled speckles and singly-scattered normal speckles shows that the triply-scattered speckle pattern has a high degree of randomness in the spatial domain and that its time-varying intensity fluctuations have a rate 72 times that of the normal speckle case in the temporal domain. Consequently, a velocimeter using the triply-scattered speckles can measure the object velocity with a greatly reduced measuring time than when using normal speckles.  相似文献   

18.
The relation between the velocity of a moving diffuse object and the mean number of integrated speckles in the certain time interval at the far-field plane of the object is obtained. By using this relation based on the first order statistics of integrated speckles, a new method of measuring the velocity of the diffuse object is proposed and experimentally verified. The first order probability density function of time-integrated speckles is also studied from which the validity of the present method is verified.  相似文献   

19.
The statistical analysis of self-mixing speckles interference using Fabry-Perot cavity is described based on the theory of the speckle and the self-mixing interference in a laser diode. Speckle signal processing based on Fourier transform is presented in this paper. The linear dependence between the spectrum mean frequency and velocity of solution is given by simulation and proved by experiment. The experimental results show that this speckle signal processing can be used to measure velocity of target.  相似文献   

20.
由散斑场和参考光的干涉图样提取散斑场复振幅、相位和强度的数值分布,并对其统计特性进行实验研究,消除了散斑场强度统计函数特别是概率密度函数的传统测量方法中噪声引起的偏差,并实现了散斑场复振幅和相位统计特性的实验研究.通过对不同散射角处散斑场的研究发现随着散射角度的增大散斑颗粒逐渐呈现出横向展宽的现象,且其平均宽度表现为各向异性,但是其概率密度函数并没有发生变化,与小角度情况一样属于圆形高斯散斑场. 关键词: 散斑 概率密度 干涉  相似文献   

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